The maven repository has the wrong jars for 6.0.5. The SF Release has date 8/16 and the repo 8/19. This leads to some nasty java.io.InvalidClassException when invoking liferay remotely (e.g. CompanyServiceHttp.getCompanyByWebId)!

The difference on the dates of the artifacts does not mean that they are different in the content, they are the same. The Maven repository has the correct artifacts since they were built and uploaded using the released tag 6.0.5. Your problem should be related to other issue. Could you open a ticket about it and let me know? I will try to help you.